Publish and Subscribe is an effective way of disseminating information to multiple users. Publish/Subscribe (pub/sub) applications can help to enormously simplify the task of getting business messages and transactions to a wide, dynamic and potentially large audience in a timely manner.
In the field of this invention it is known that pub/sub applications are typically written so that a “community” of clients with a common purpose all connect in to a particular broker, to enable them to send and receive messages amongst themselves. An obvious example is producer/consumer applications, where one set of clients produce data and another set consume that data. Another example is in online gaming, where individual clients connect into a central “hub” to gain access to common services like billing, game updates, high-scores, etc.
However, a problem with this arrangement is that the pub/sub architecture is “static”: things become difficult if one of the clients needs to get access to some data which is being published to a different broker somewhere else in the world, for example, if it only occasionally needs to go to update some data table (e.g., average rainfall in some city over a year), or perhaps if an online gaming client needs to report a bug to the game manufacturer, or publish a new high ‘high score’ for global recognition.
On the World Wide Web, a user can easily ‘jump off’ the ‘current’ web server and go to a different one, simply by following a hyperlink. With Web Services, a user can look up the connection information for a service that the user wishes to make use of. However, heretofore, such alternate sourcing of information has not been possible for pub/sub.
It is possible for a client to disconnect from its “current” broker, and reconnect to a different one, but that assumes that all clients have “external” connectivity to allow them to reach the remote brokers, and in the closed world of (say) an online gaming system, that is often not the case (and there are reasons such as security why the clients should not be given such “general” access). So the problem to be solved is gaining pub/sub access to a remote broker given the restricted environment of a closed community pub/sub system.
A need therefore exists for users of a closed pub/sub community, connected to a central broker facility, to be able to exchange pub/sub messages with other, remote brokers, without gaining a direct connection to those brokers, wherein the abovementioned disadvantage(s) may be alleviated.